//===----------------------------------------------------------------------===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// SPDX-FileCopyrightText: Copyright (c) 2023 NVIDIA CORPORATION & AFFILIATES.
//
//===----------------------------------------------------------------------===//

#ifndef TEST_SUPPORT_CONTAINER_DEBUG_TESTS_H
#define TEST_SUPPORT_CONTAINER_DEBUG_TESTS_H

#include <ciso646>
#ifndef _LIBCUDACXX_VERSION
#  error This header may only be used for libc++ tests
#endif

#ifndef _CCCL_ENABLE_DEBUG_MODE
#  error The library must be built with the debug mode enabled in order to use this header
#endif

#include <cuda/std/cassert>

#include <__debug>
#include <cstddef>
#include <cstdlib>
#include <utility>

#include "check_assertion.h"
#include "test_allocator.h"
#include "test_macros.h"

namespace IteratorDebugChecks
{

enum ContainerType
{
  CT_None,
  CT_String,
  CT_Vector,
  CT_VectorBool,
  CT_List,
  CT_Deque,
  CT_ForwardList,
  CT_Map,
  CT_Set,
  CT_MultiMap,
  CT_MultiSet,
  CT_UnorderedMap,
  CT_UnorderedSet,
  CT_UnorderedMultiMap,
  CT_UnorderedMultiSet
};

constexpr bool isSequential(ContainerType CT)
{
  return CT >= CT_Vector && CT <= CT_ForwardList;
}

constexpr bool isAssociative(ContainerType CT)
{
  return CT >= CT_Map && CT <= CT_MultiSet;
}

constexpr bool isUnordered(ContainerType CT)
{
  return CT >= CT_UnorderedMap && CT <= CT_UnorderedMultiSet;
}

constexpr bool isSet(ContainerType CT)
{
  return CT == CT_Set || CT == CT_MultiSet || CT == CT_UnorderedSet || CT == CT_UnorderedMultiSet;
}

constexpr bool isMap(ContainerType CT)
{
  return CT == CT_Map || CT == CT_MultiMap || CT == CT_UnorderedMap || CT == CT_UnorderedMultiMap;
}

constexpr bool isMulti(ContainerType CT)
{
  return CT == CT_MultiMap || CT == CT_MultiSet || CT == CT_UnorderedMultiMap || CT == CT_UnorderedMultiSet;
}

template <class Container, class ValueType = typename Container::value_type>
struct ContainerDebugHelper
{
  static_assert(std::is_constructible<ValueType, int>::value, "must be constructible from int");

  static ValueType makeValueType(int val = 0, int = 0)
  {
    return ValueType(val);
  }
};

template <class Container>
struct ContainerDebugHelper<Container, char>
{
  static char makeValueType(int = 0, int = 0)
  {
    return 'A';
  }
};

template <class Container, class Key, class Value>
struct ContainerDebugHelper<Container, std::pair<const Key, Value>>
{
  using ValueType = std::pair<const Key, Value>;
  static_assert(std::is_constructible<Key, int>::value, "must be constructible from int");
  static_assert(std::is_constructible<Value, int>::value, "must be constructible from int");

  static ValueType makeValueType(int key = 0, int val = 0)
  {
    return ValueType(key, val);
  }
};

template <class Container, ContainerType CT, class Helper = ContainerDebugHelper<Container>>
struct BasicContainerChecks
{
  using value_type     = typename Container::value_type;
  using iterator       = typename Container::iterator;
  using const_iterator = typename Container::const_iterator;
  using allocator_type = typename Container::allocator_type;
  using traits         = std::iterator_traits<iterator>;
  using category       = typename traits::iterator_category;

  static_assert(std::is_same<test_allocator<value_type>, allocator_type>::value,
                "the container must use a test allocator");

  static constexpr bool IsBiDir = std::is_convertible<category, std::bidirectional_iterator_tag>::value;

public:
  static void run()
  {
    run_iterator_tests();
    run_container_tests();
    run_allocator_aware_tests();
  }

  static void run_iterator_tests()
  {
    TestNullIterators<iterator>();
    TestNullIterators<const_iterator>();
    if constexpr (IsBiDir)
    {
      DecrementBegin();
    }
    IncrementEnd();
    DerefEndIterator();
  }

  static void run_container_tests()
  {
    CopyInvalidatesIterators();
    MoveInvalidatesIterators();
    if constexpr (CT != CT_ForwardList)
    {
      EraseIter();
      EraseIterIter();
    }
  }

  static void run_allocator_aware_tests()
  {
    SwapNonEqualAllocators();
    if constexpr (CT != CT_ForwardList)
    {
      // FIXME: This should work for both forward_list and string
      SwapInvalidatesIterators();
    }
  }

  static Container makeContainer(int size, allocator_type A = allocator_type())
  {
    Container C(A);
    if constexpr (CT == CT_ForwardList)
    {
      for (int i = 0; i < size; ++i)
      {
        C.insert_after(C.before_begin(), Helper::makeValueType(i));
      }
    }
    else
    {
      for (int i = 0; i < size; ++i)
      {
        C.insert(C.end(), Helper::makeValueType(i));
      }
      assert(C.size() == static_cast<std::size_t>(size));
    }
    return C;
  }

  static value_type makeValueType(int value)
  {
    return Helper::makeValueType(value);
  }

private:
  // Iterator tests
  template <class Iter>
  static void TestNullIterators()
  {
    // testing null iterator
    Iter it;
    EXPECT_DEATH(++it);
    EXPECT_DEATH(it++);
    EXPECT_DEATH(*it);
    if constexpr (CT != CT_VectorBool)
    {
      EXPECT_DEATH(it.operator->());
    }
    if constexpr (IsBiDir)
    {
      EXPECT_DEATH(--it);
      EXPECT_DEATH(it--);
    }
  }

  static void DecrementBegin()
  {
    // testing decrement on begin
    Container C       = makeContainer(1);
    iterator i        = C.end();
    const_iterator ci = C.cend();
    --i;
    --ci;
    assert(i == C.begin());
    EXPECT_DEATH(--i);
    EXPECT_DEATH(i--);
    EXPECT_DEATH(--ci);
    EXPECT_DEATH(ci--);
  }

  static void IncrementEnd()
  {
    // testing increment on end
    Container C       = makeContainer(1);
    iterator i        = C.begin();
    const_iterator ci = C.begin();
    ++i;
    ++ci;
    assert(i == C.end());
    EXPECT_DEATH(++i);
    EXPECT_DEATH(i++);
    EXPECT_DEATH(++ci);
    EXPECT_DEATH(ci++);
  }

  static void DerefEndIterator()
  {
    // testing deref end iterator
    Container C                        = makeContainer(1);
    [[maybe_unused]] iterator i        = C.begin();
    [[maybe_unused]] const_iterator ci = C.cbegin();

    if constexpr (CT != CT_VectorBool)
    {
      i.operator->();
      ci.operator->();
    }
    ++i;
    ++ci;
    assert(i == C.end());
    EXPECT_DEATH(*i);
    EXPECT_DEATH(*ci);
    if constexpr (CT != CT_VectorBool)
    {
      EXPECT_DEATH(i.operator->());
      EXPECT_DEATH(ci.operator->());
    }
  }

  // Container tests
  static void CopyInvalidatesIterators()
  {
    // copy invalidates iterators
    Container C1                = makeContainer(3);
    [[maybe_unused]] iterator i = C1.begin();
    Container C2                = C1;

    if constexpr (CT == CT_ForwardList)
    {
      iterator i_next = i;
      ++i_next;
      EXPECT_DEATH(C2.erase_after(i));
      C1.erase_after(i);
      EXPECT_DEATH(*i_next);
    }
    else
    {
      EXPECT_DEATH(C2.erase(i));
      C1.erase(i);
      EXPECT_DEATH(*i);
    }
  }

  static void MoveInvalidatesIterators()
  {
    // copy move invalidates iterators
    Container C1                = makeContainer(3);
    [[maybe_unused]] iterator i = C1.begin();
    Container C2                = std::move(C1);

    if constexpr (CT == CT_ForwardList)
    {
      EXPECT_DEATH(C1.erase_after(i));
      C2.erase_after(i);
    }
    else
    {
      EXPECT_DEATH(C1.erase(i));
      C2.erase(i);
      EXPECT_DEATH(*i);
    }
  }

  static void EraseIter()
  {
    // testing erase invalidation
    Container C1      = makeContainer(2);
    iterator it1      = C1.begin();
    iterator it1_next = it1;
    ++it1_next;
    Container C2 = C1;
    EXPECT_DEATH(C2.erase(it1)); // wrong container
    EXPECT_DEATH(C2.erase(C2.end())); // erase with end
    C1.erase(it1_next);
    EXPECT_DEATH(C1.erase(it1_next)); // invalidated iterator
    C1.erase(it1);
    EXPECT_DEATH(C1.erase(it1)); // invalidated iterator
  }

  static void EraseIterIter()
  {
    // testing erase iter iter invalidation
    Container C1      = makeContainer(2);
    iterator it1      = C1.begin();
    iterator it1_next = it1;
    ++it1_next;
    Container C2      = C1;
    iterator it2      = C2.begin();
    iterator it2_next = it2;
    ++it2_next;
    EXPECT_DEATH(C2.erase(it1, it1_next)); // begin from wrong container
    EXPECT_DEATH(C2.erase(it1, it2_next)); // end   from wrong container
    EXPECT_DEATH(C2.erase(it2, it1_next)); // both  from wrong container
    C2.erase(it2, it2_next);
  }

  // Allocator aware tests
  static void SwapInvalidatesIterators()
  {
    // testing swap invalidates iterators
    Container C1 = makeContainer(3);
    Container C2 = makeContainer(3);
    iterator it1 = C1.begin();
    iterator it2 = C2.begin();
    swap(C1, C2);
    EXPECT_DEATH(C1.erase(it1));
    if (CT == CT_String)
    {
      EXPECT_DEATH(C1.erase(it2));
    }
    else
    {
      C1.erase(it2);
    }
    // C2.erase(it1);
    EXPECT_DEATH(C1.erase(it1));
  }

  static void SwapNonEqualAllocators()
  {
    // testing swap with non-equal allocators
    Container C1 = makeContainer(3, allocator_type(1));
    Container C2 = makeContainer(1, allocator_type(2));
    Container C3 = makeContainer(2, allocator_type(2));
    swap(C2, C3);
    EXPECT_DEATH(swap(C1, C2));
  }

private:
  BasicContainerChecks() = delete;
};

} // namespace IteratorDebugChecks

#endif // TEST_SUPPORT_CONTAINER_DEBUG_TESTS_H
